# 多线程

from random import randint
from time import time, sleep


def download_task(filename):
    print("开始下载%s..." % filename)
    time_to_download = randint(5, 10)
    sleep(time_to_download)
    print("%s下载完成！耗费了%d秒" % (filename, time_to_download))


def main():
    start = time()
    download_task("Python从入门到住院.pdf")
    download_task("Peking Hot.avi")
    end = time()
    print("总共耗费了%.2f秒." % (end - start))


if __name__ == "__main__":
    main()